Tokina 16-28mm f/2.8 - Any info on Aquatica extensions/gears?

I'm considering getting an Aquatica housing for my 5D mark II with a Tokina 16-28mm f/2.8 lens, but this lens isn't included in Aquatica's current lens charts. Has anyone tried housing this lens yet, and if so, are there any currently available extensions and zoom gears that are suitable for it?

I haven't purchased the lens yet, so can't measure it, but it looks to be very similar in size and shape to the Nikon 24-24mm f/2.8, or a little similar to the Canon 16-35mm f/2.8. Aquatica extension 18458 and zoom gear 18722 with the 14-24mm, or extension 18457 and zoom gear 18708 with the 16-35mm. I'm tempted to just try getting the extension and zoom for the 14-24mm and hoping they fit, but obviously this is quite a gamble.

Dave, I don't have the lens available for physical measurement or for testing on our own optical bench, so no data, but in a very non scientific way, I overlapped a picture of the Tokina 11-16mm over the Tokina 16-28mm in the Nikon version, they have multiple electronic contact points just behind the lens mount that are both very precisely located on all lenses and very helpful as reference point, when I match the contacts position, I come up with what seem to be the same zoom ring size, so a 18722 gear would be a good start in my opinion.

About the port extension, I did the same, overlapped a picture of the Nikon 14-24mm over the Tokina 16-28mm using the same electronic contacts as reference, I come up with a Tokina lens that is +/- a few millimetre (looks like 5mm) longer than the Nikon. So my hunch would be for # 18458 (same as the 14-24mm).

Please remember that this is not official Aquatica data, but my own educated guess as to what would work, lenses that are on the Aquatica lens chart are document both physically and optically. So I could be wrong, but accumulated experience does have its merits as well.

Thanks Jean, much appreciated. I'll be receiving the lens before purchasing the housing, so if it would help, I could provide some accurate measurements of the lens when I have it. (External measurements would be easy, diaphragm position a little more difficult.)

Hi Jean,
Here are my measurements of the lens. All length measurements are taken from the shoulder of the bayonet mount - the circular metal face that presses against the front of the camera when the bayonet is secured. Could you please let me know if these change your guesses about which extensions and gears would be appropriate?

Hi Jean,
I received the housing today, and while the port and extension look good, the 18722 gear unfortunately doesn't fit on the zoom ring, even with the gear's o-rings removed! Is there a larger size gear you could recommend? About 2mm wider in diameter would be perfect.

Hi Jean,
I've just returned from overseas, and had a chance to accurately measure my 16-28mm with callipers, alongside the Canon 24-70mm f/2.8. The two lenses have the zoom ring the same distance from the bayonet shoulder, but the 16-28mm zoom ring is smaller than the 24-70. (74.5mm diameter for the 16-28mm, compared with 83.5mm for the 24-70mm.) I had been hoping the 18723 ring for the 24-70mm would fit the 16-28mm, but from those measurements it looks like it will be too large. Is there any zoom gear sized between the 18722 and 18723?

Also, could you please tell me the length of the standard macro port (18428) and the low profile macro port (18429), in terms of distance from the bayonet mount to the glass? I'm also trying to figure out whether I'd be able to use different lenses behind one without needing many different extensions. I.e. Using the 28mm or 50mm primes, or adding a teleconverter to the 100mm macro, I'd like to try to calculate whether I'd get vignetting due to the port being too long, or have the lens hit the glass due to it being too short.

Also, more generally, is there currently a zoom gear sized between 18722 and 18723, and if not, would Aquatica consider producing one specifically to fit this lens? Similarly, assuming your initial 75mm ideal extension calculation is correct, would Aquatica consider producing a new extension to suit this lens?

Dave, we have a 74.5mm extension it is the 18464, it is designed to be used with the Canon 16-35mm and has a manual focus control knob for this Canon lens, you use this extension, you wont be able to use the manual focus option but the length would be the right one, about the gear, they are produced in large batch and yours being the only request so far means that we are a long way from having the minimum requirement for starting a production run.

What you could do (and many with special project lenses do) is take your 18722 and lens to a local machine shop with a lathe and asked them to open up the gear diameter a bit (bringing the lens along will insure a nice tight fit)